Biometric recognition using a classification neural network

Claim 1

A biometric recognition system for authenticating biometric indicia of a user, the system comprising: data storage means for storing a plurality of master pattern sets, each master pattern set corresponding one of a plurality of authorized users, each of the master pattern sets defined by a plurality of master features and master orientation data of the plurality of master features; vector generation means for producing a comparison vector representing the level of similarity between a master pattern set and the biometric indicia; and a neural network for producing classification designators based on the comparison vector, wherein the classification designators are indicative of whether the user's biometric indicia should be authenticated; wherein the vector generation means comprises: identification means for identifying sample features in the biometric indicia that best match each of the master features; pattern generation means for generating sample orientation data based on the sample features that best match each of the master features; and means for comparing the master orientation data and the sample orientation data to produce comparison orientation data; wherein the comparison vector is based on the comparison orientation data and is also based on the similarity of the master features and their corresponding sample features; and the master pattern sets are derived using the following equation: ##EQU5## where S is the set of all m-by-m features in an image, with the exception of R, which is a reference feature; R ij is an (i, j)th pixel gray level in feature R; I ij i s an (i, j)th pixel gray level in I; and R and I are mean gray levels within the respective features.

Claim 14

A method for generating a master pattern set of a biometric indicia of a user, comprising the steps of: (a) acquiring an image of the biometric indicia to produce a biometric pattern image, wherein the biometric pattern image includes a plurality of features; (b) comparing each feature in the biometric pattern image with all other features in the biometric pattern image; (c) assigning a uniqueness value to each feature in the biometric pattern image based on the results of comparing step (b); (d) choosing, based on the uniqueness values, from the features in the biometric pattern image a plurality of master features; (e) defining master patterns based on the master features; (f) storing the master patterns and master features as the master pattern set, wherein assigning step (c) uses the following equation: ##EQU7## where S is the set of all m-by-m features in an image, with the exception of R, which is a reference feature; R ij is an (i, j)th pixel gray in feature R; I ij is an (i, j)th pixel gray level in I; and R and I are mean gray levels within the respective features.

Claim 15

A method for generating a master pattern set of a biometric indicia of a user, comprising the steps of: (a) acquiring an image of the biometric indicia to produce a biometric pattern image, wherein the biometric pattern image includes a plurality of features; (b) comparing each feature in the biometric pattern image with all other features in the biometric pattern image; (c) assigning a uniqueness value to each feature in the biometric pattern image based on the results of comparing step (b); (d) choosing, based on the uniqueness values, from the features in the biometric pattern image a plurality of master features; (e) defining master patterns based on the master features; (f) storing the master patterns and master features as the master pattern set, wherein assigning step (c) uses the following equation: ##EQU7## where S is the set of all m-by-m features in an image, with the exception of R, which is a reference feature; R ij is an (i, j)th pixel gray in feature R; I ij is an (i, j)th pixel gray level in I; and R and I are mean gray levels within the respective features.

Claim 20

A method for authenticating a biometric pattern of a user, in which authorized biometric patterns are stored and represented by corresponding master pattern sets comprised of a plurality of master patterns based on a plurality of master features in the corresponding biometric pattern, comprising the steps of: (a) acquiring an image of a biometric pattern to be authenticated and producing therefrom a sample pattern image, wherein the sample pattern image includes a plurality of sample features; (b) retrieving a master pattern set; (c) comparing each master feature in the retrieved master pattern set with the sample features and determining therefrom which sample feature best matches each master feature, and producing therefrom a set of matched sample features; (d) defining sample patterns based on the set of matched sample features; (e) comparing the sample patterns with the master patterns; (f) authenticating the sample pattern image upon a favorable comparison step (e), wherein comparing step (c) uses the following equation: ##EQU8## where S is the set of all m-by-m features in an image, with the exception of R, which is a reference feature; R ij is an (i, j)th pixel gray level in feature R; I ij is an (i, j)th pixel gray level in I: and R and I are mean gray levels within the respective features.

Claim 21

A method for authenticating a biometric pattern of a user, in which authorized biometric patterns are stored and represented by corresponding master pattern sets comprised of a plurality of master patterns based on a plurality of master features in the corresponding biometric pattern, comprising the steps of: (a) acquiring an image of a biometric pattern to be authenticated and producing therefrom a sample pattern image, wherein the sample pattern image includes a plurality of sample features; (b) retrieving a master pattern set; (c) comparing each master feature in the retrieved master pattern set with the sample features and determining therefrom which sample feature best matches each master feature, and producing therefrom a set of matched sample features; (d) defining sample patterns based on the set of matched sample features; (e) comparing the sample patterns with the master patterns; (f) authenticating the sample pattern image upon a favorable comparison step (e), wherein comparing step (c) uses the following equation: ##EQU8## where S is the set of all m-by-m features in an image, with the exception of R, which is a reference feature; R ij is an (i, j)th pixel gray level in feature R; I ij is an (i, j)th pixel gray level in I: and R and I are mean gray levels within the respective features.

Claim 26

A method for authenticating a biometric pattern of a user, comprising the steps of: storing a master pattern set from the user, the master pattern set defined by a plurality of master features and master orientation data of the plurality of master features; acquiring a sample biometric pattern of a user to be authenticated; identifying sample features in the sample biometric pattern that best match each of the plurality of master features; generating sample orientation data based on a pattern generated by the identified sample features; comparing the master orientation data and the sample orientation data to produce comparison orientation data; producing a comparison vector based on the similarity of the plurality of master features and their corresponding identified sample features and based on the comparison orientation data; producing classification designators based on the comparison vector; and authenticating the biometric pattern if the classification designators indicate a match, wherein the comparing step uses the following equation: ##EQU9## where S is the set of all m-by-m features in an image, with the exception of R, which is a reference feature; R ij an (i, j)th pixel gray level in feature R; I ij is an (i, j)th pixel gray level in I; and R and I are mean gray levels within the respective features.

Claim 27

A method for authenticating a biometric pattern of a user, comprising the steps of: storing a master pattern set from the user, the master pattern set defined by a plurality of master features and master orientation data of the plurality of master features; acquiring a sample biometric pattern of a user to be authenticated; identifying sample features in the sample biometric pattern that best match each of the plurality of master features; generating sample orientation data based on a pattern generated by the identified sample features; comparing the master orientation data and the sample orientation data to produce comparison orientation data; producing a comparison vector based on the similarity of the plurality of master features and their corresponding identified sample features and based on the comparison orientation data; producing classification designators based on the comparison vector; and authenticating the biometric pattern if the classification designators indicate a match, wherein the comparing step uses the following equation: ##EQU9## where S is the set of all m-by-m features in an image, with the exception of R, which is a reference feature; R ij an (i, j)th pixel gray level in feature R; I ij is an (i, j)th pixel gray level in I; and R and I are mean gray levels within the respective features.